Craig Harris Zello, 50, of Hagerstown has been charged with first- and second-degree attempted murder, assault, reckless endangerment and weapons violation charges in the incident at the Thomas B. Finan Hospital Center, according to Maryland State Police.

Authorities say the victim, a registered nurse whose name was not released, was trying to restrain a combative Zello on Monday morning when Zello stuck him in the head with a 7-inch galvanized spike. The spike, police said, was still lodged in the nurse's head when state troopers arrived.

The victim was taken to the Western Maryland Regional Medical Center where his injuries initially were considered serious. But a police spokesman said Tuesday that the victim had been released and had suffered a wound no deeper than about 3 inches.

"It was not serious," said Judy Hott, CEO of Finan center, of the injury, adding that she is pulling together a safety task force to review the attack and "avoid anything remotely like this happening again."

Zello was taken to the Western Maryland Regional Medical Center for evaluation before being transferred to the state police's Cumberland barracks. He is being held in jail without bail. Police said they don't know how Zello obtained the spike.

The Finan center provides mental health services to adults and is consistently filled to its capacity of 88 patients.

The hospital accepts patients who come voluntarily, are involuntarily committed or whom the courts have ordered to the hospital for evaluation after arrest, Hott said. Patients are admitted for short stays, weeks or months. Depending on risk assessments and evaluations, they are under various levels of supervision, Hott said, with some allowed to come and go from the center.

Health privacy laws precluded Hott from disclosing any details about Zello or his stay at the Finan center. An attorney for Zello was not listed in state court records and relatives could not be located.

A 31-year-old man who was sentenced to 20 years in prison in Baltimore after he pleaded guilty to possessing 5.9 grams of marijuana won an appeal Wednesday invalidating the plea — raising the possibility that he will be released.